Two track folding door construction



y 1970 J. A. SMART 3,509,934

TWO TRACK FOLDING DOOR CONSTRUCTION Filed NOV. 12, 1968 3 Sheets-Sheet 1 Fig./ 6

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, Jay A Smart IN VEN TOR.

BY M 0,

May 5, 1970 J. A. SMART TWO TRACK FOLDING DOOR CONSTRUCTION 3 Sheets-Sheet 2 Filed Nov. 12, 1968 /m r m w W 6 8 m 8 N\ 4 5 0 A 5 2/ 4 5 n. 5 A/ A; kn n. n I v y M l A- R E 0 w 5 I Q5 Kw [20v m min]. 3 v U M i 4 0 0 r a t w m m 6 F Q P... 7 k k a I fi 2. w fi w j N m IN VENTOR. @762. E Attorney:

1970v J. A. SMART 3,509,934

TWO TRACK FQLDING DOOR CONSTRUCTION Filed Nov. 12. 1968 "s Sheets-Sheet 5 Fig. 5

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Jay A. Smurf INVENTOR.

BY Mz W,

United States Patent US. Cl. 160-84 15 Claims ABSTRACT OF THE DISCLOSURE An accordion type folding door comprising a pair of lead post interconnected sections, each of which is defined by a plurality of hinge interconnected panels, and an overhead support and control system therefor including two laterally spaced tracks and a lead post mounting roller assembly. The roller assembly includes two roller units for engagement in the two tracks, each unit comprising a plurality of rollers which are so orientated as to positively engage within the track for free non-twisting or binding movement therealong and in a manner whereby an off-center pull on the door will not affect the free rolling movement of the roller assembly along the tracks.

The instant invention is generally related to folding accordion-type doors, and more particularly relates to a hollow core door of this type wherein interconnected parallel door sections are utilized.

In conjunction with the above, it is a primary object of the instant invention to provide a support and control assembly for such a double door wherein a positive syn chronized movement of both sections can be easily effected from the lead post, regardless of the size of the particular door or whether or not the door moving force applied on the lead post is off-center or from one side theref, as will most commonly occur.

In order to achieve the desired smooth non-binding synchronized movement of the door sections as a single unit, especially in large and/or heavy installations, a unique lead post roller assembly support plate is provided whereby, regardless of the direction of pull on the lead post, a straight non-twisting movement thereof along the track assembly will be effected, this in turn resulting in a linear synchronized movement of the two door sections therewith. The roller assembly plate basically includes a pair of laterally spaced upwardly directed flanges, each of which mounts a plurality of pairs of rollers, selected ones of which engage the bottom of the track so as to define a positive support for the lead post and adjoining end of the door, and others of which engage the top of the track so as to positively seat the support rollers and provide for a non-binding travel of the rollers along the track. This non-binding travel of the rollers is further enhanced by elongated guiding lips within the tracks and a limited movement accommodating mounting of the roller shafts allowing the rollers to adjust slightly and continue in a non-binding manner along the tracks notwithstanding a slight twisting in the support plate itself due to an off-center force on the lead post.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a side elevational view of a portion of a folding door constructed in accordance with the instant invention, a section thereof broken away for purposes of illustration;

FIG. 2 is an enlarged cross-sectional view taken substantially on a plane passing along line 22 in FIG. 1;

3,509,934 Patented May 5, 1970 "ice FIG. 3 is an enlarged cross-sectional view taken substantially on a plane passing along line 3--3 in FIG. 1;

FIG. 4 is a cross-sectional view taken substantially on a plane passing along line 44 in FIG. 3;

FIG. 5 is a cross-sectional view taken substantially on a plane passing along line 55 in FIG. 3;

FIG. 6 is an enlarged cross-sectional view taken substantially on a plane passing along line 6-6 in FIG. 1;

FIG. 7 is an enlarged perspective view of the lead post roller assembly;

FIG. 8 is an enlarged cross-sectional detail of a roller axle journal; and

FIG. 9 is an enlarged detail illustrating a support roller seated Within the lower portion of a track.

Referring now more specifically to the drawings, reference numeral 10 is used to generally designate an accordion-type folding door constructed in accordance with the instant invention. This door includes a pair of laterally spaced door sections 12, each defined by a plurality of rigid panels 14 interconnected by full height flexible vinyl hinges 16. The two sections, when fully extended, are spaced approximately six inches from each other.

One end of the two section door 10 is to have the sections thereof connected to a suitable jamb (not illustrated), while the other end of the two sections 12 are engaged with a common full height rectangular lead post 18, note FIG. 2 in particular. The lead post 18 actually has one edge thereof rigidly affixed centrally along a rigid panel 20 orientated transversely of the sections 12 and hingedly connected, along the opposite edges thereof, to a pair of rearwardly directed panels 22 which are in turn of a width substantially less than that of the main panels 14 to which they are hingedly engaged, also by the full height flexible vinyl hinge strips 16. This basic door construction is shown in ap-plicants copending application Ser. No. 732,477, filed Apr. 25, 1968, as a continuation-in-part of now abandoned application Ser. No. 563,559, filed July 7, 1966. Such a structural arrangement is particularly useful in providing a movable partition with significant insulative qualities, both fire and sound, with the two panel formed sections having clip mounted inner insulated blankets or liners 24 thereon which cooperate with the normally heavy gauge extruded aluminum panels 14. However, while significant advantages reside in such hollow core doors, a particular problem which has arisen in connection therewith is the difficulty in providing for a smooth folding and unfolding of the doors, especially when doors of a substantial size are involved, for example ceiling height doors used to partition rooms. The instant invention overcomes these difiiculties primarily through the provision of a unique lead post roller assembly 26 which supports the lead post in an overhead track assembly 28 in a non-binding and positive guiding manner whereby even an off-center pull on the lead post, such as will normally occur when the {door is to be opened or closed from one side thereof, will result in a straight guiding and controlling movement along the track assembly with the door, particularly through the arrangement of the panels 20 and 22, following smoothly along therewith.

With the particular reference to FIGS. 6 and 7, it will be noted that the lead post roller plate assembly includes a plate 30, approximately six inches wide and three inches deep, terminating at the opposed edges thereof in upturned roller mounting flanges 32, each in turn having a thickened head portion 34- along the full depth thereof. The plate 30 is locked into the upper end of the lead post 18 by means of a pair of centrally located depending cars 36 which are laterally spaced from each other and of a front to rear depth so as to closely conform to the interior of the hollow lead post 18 into which they are introduced and within which they are locked by an appropriate transversely extending bolt or pin 38. The upper end of the lead post 18 normally seats directly against the undersurface of the plate 30, resulting in a permanent rigid locking of the assembly 26- to the upper end of the lead post 18.

Each of the roller units includes, on each enlarged head 34, forward and rear pairs of rollers 40 mounted on horizontal coplanar axles 42 received through axle journalling' openings 44 defined through the corresponding enlarged full depth head 34 adjacent the opposed ends thereof. Each roller unit additionally includes a central pair of rollers 46 located between the two pairs of rollers 40 and mounted on an axle 48 which is both horizontal and parallels the axles 42 in a slightly elevated plane relative thereto, thereby elevating the pair of rollers 46 relative to the two pairs of equal size rollers 40 as will be best appreciated from FIGS. 4 and 5. The transverse flange passage journaling the axle 48 is of the same shape and configuration as the passages 44 associated with the axles 42, attention being directed to FIG. 8 for a crosssectional detail thereof. These passages are relieved or enlarged to the opposite sides of the annular central portion thereof, this central portion closely although rotatably receiving the corresponding axles with the arcuate surface thereof enabling a slight angular displacement of the roller axle. In addition, noting FIG. 6 in particular, each roller or wheel 40 or 46 includes a central hub portion which is of a width so as to allow for a slight longitudinal sliding of the roller on the corresponding shaft between an enlarged retaining head 50 on the corresponding end of the shaft and the enlarged roller unit mounting head 34, thus providing for further play in the pairs of rollers which make up each roller unit.

Referring now particularly to FIGS. 3, 6 and 9, the track assembly 28 includes a pair of laterally spaced parallel elongated tracks 52, each including a pair of parallel laterally spaced tracking grooves '54 spaced so as to receive one of the plate flanges 32 therebetween with the opposed rollers of each pair of rollers being received therein. Each of the tracking grooves 54 is of a V-shaped cross-section, noting FIG. 9 in particular, with the corresponding roller, such being one of the rollers 40, tracking along the opposed inclined walls of the tracking groove 54 and being retained therein against lateral displacement by a vertical flange 56 on the outer inclined wall provided immediately adjacent the roller 40, and a guide lip or ridge 58 in generally opposed coplanar relation to the flange 56 and positioned immediately adjacent the opposite side of the roller 40. Thus the roller 40 is confined between the ridge -8 and the flange 56 so as to track longitudinally along the tracking groove 54.

As previously indicated, the central pair of rollers 46 of each roller unit is offset upwardly relative to the two end pairs of rollers 40. This oflset is sufficient so as to rollingly engage the central pair of rollers 46 with the flat surface defining plate 60 of each track 52 in overlying relation to the corresponding tracking grooves 54 while the two end pairs of rollers 40 are seated and engaged within the underlying tracking grooves 54. In this manner, the rollers 40, which actually support the assembly 26, are maintained in positive tracking engagement within the tracking grooves 54 and upward displacement'thereof is eifectively prevented by the downward pressure exerted by the central pair of rollers 46. The support and guiding rollers 40 are thus prevented from binding, riding out of the track, or being thrown out of alignment, the guiding rib or ridge 58 and opposed guiding flange 56 contributing to prevent lateral binding of the rollers. Furthermore, the slight play provided for in the roller axles and the mounting of the rollers on the axles allows the rollers to move and adjust freely as they travel along the track even though the plate 30 may be twisted slightly due to an olf-center or side pull on the lead post 18, each as would frequently occur when operating the door from one side thereof, particularly when a door of any substantial size is involved.

.Thus, with this particularly defined roller assembly and cooperating track assembly, it will be recognized that a smooth positive movement of the door can be effected. Any longitudinal movement of one of the roller units is, through the rigid plate 30, immediately transmitted to the other roller unit, resulting in an equalized pull or push on the folding door sections 12 and a synchronized collapsing or expanding of the sections, the force being introduced to the main panels 14 of each section through both the transversely connected panel 20 and the two rearwardly directed force transmitting relatively narrow panels 22. Incidently, each of the main panels 14 is also supported directly from the overhead track 52 by means of a pair of rollers 62 received within the tracking grooves 54 and connected by an elongated stem 64 to the panel 14 itself.

With reference to FIGS. 2, 3 and 6, it will be noted that the track assembly 28 also includes an air chamber 66 defined between the opposed parallel tracks 52 by means of a perforated partition 68 resting on opposed inwardly projecting support flanges 70 on the tracks 52. This chamber 66 communicates directly with the hollow core of the door 10 whereby an air flow to and from the core can readily be effected through the overhead chamber 66 during both a collapsing and opening of the door 10, this contributing to the ease of operation of the door.

Applicants copending application, Ser. No. 661,863, filed Aug. 21, 1967, now Pat. No. 3,447,584 is of interest in illustrating this air release construction which finds particular usefulness in insulated partitions. Along these lines, while not illustrated, it is contemplated that the door sections 12 of the instant invention include flexible sweeps along the upper and lower edges thereof, such section mounted sweeps flexibly engaging both the floor and the upper bounding surface of the door, for example the track assembly fasciae 72 provided immediately outward of the tracks 52. The insulation of the top of the door 10 is carried through the lead post roller assembly 26 through the provision of a compressible foam plastic pad 74 fitted against the under-surface of the plate 30, about the dependent mounting ears 36, and upturned along the opposed edges thereof so as to lie against the outer surface of the flanges 32 and into engagement with the outer one of each pair of tracking grooves 54 so as to slidingly seal thereagainst and form and effect a continuation of the normally provided sweeps which have been specifically left oif of the drawings herein for purposes of clarity.

From the foregoing, it should be appreciated that a unique folding door construction has been defined, such construction basically consisting of a hollow core folding door defined by two independently mounted poor sections controlled from a common lead post unit whereby a synchronized movement of both sections can be elfected in a smooth non-binding manner regardless of the size of the section formed door or the weight associated therewith either because of the size or through the provision of internal insulation. The necessary smooth operation and control of the door arises through the provision of a specific lead post mounting and supporting roller assembly which is guided within a cooperating pair of roller aligning and stabilizing tracks. In addition, the lead post itself is engaged through a specific panel arrangement with the two door sections for a transmittal of the smooth guided movement of the lead post to the sections, the lead post roller assembly accommodating itself to any twist or off-center pull introduced into the lead post so as to continuously track longitudinally along the tracks in .a nonbinding manner which insures the necessary section expanding and contracting movement of the lead post.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. Folding door construction comprising a pair of laterally spaced generally parallel folding door sections, a lead post interconnecting said sections at one end thereof, an overhead track assembly mounted along the path of movement to be taken by said door construction, said track assembly including a pair of elongated laterally spaced tracks in overlying relation to the pair of folding door sections, roller means engaged between each section at spaced points therealong and the corresponding overlying track, and a lead post roller assembly mounted on said lead post and engaged with said track assembly, said roller assembly comprising a pair of upwardly projecting laterally spaced roller units, and rigid means connecting said roller units to the upper end of said lead post in laterally spaced relation to the opposite sides of said lead post, said roller units rollingly engaging in said pair of tracks for longitudinal movement therealong in conjunction with the lead post connected thereto.

2. The construction of claim 1 wherein each track comprises upper and lower tracking surfaces, each roller unit including support roller means engaged with the lower tracking surface of the corresponding track, and retaining roller means engaged with the upper tracking surface of the corresponding track for a retention of the support roller means in engagement with the lower tracking surface.

3. The construction of claim 2 wherein each track includes a pair of laterally spaced upwardly opening tracking grooves defining the lower tracking surfaces, said support roller means comprising two aligned pairs of rollers, one roller of each pair of rollers engaging in each of the tracking grooves, said retaining roller means comprising a single pair of rollers positioned between the two pairs of rollers comprising the support roller means, each of the retaining rollers being positioned in vertically spaced relation above one of the tracking grooves.

4. The construction of claim 3 wherein each tracking groove comprises a pair of downwardly converging side walls, each side wall including a longitudinally extending vertical projecting portion thereon between which the support rollers are confined for longitudinal movement in engagement with the converging side walls in a manner whereby lateral movement of the support rollers is substantially precluded.

5. The construction of claim 4 wherein each pair of rollers is mounted for limited wobble movement relative to the rigid means connecting the roller units to the lead post whereby straight tracking orientation of the rollers within the track is retained notwithstanding the introduction of an off-center force on the lead post.

6. The construction of claim 5 wherein the rigid means connecting the roller units to the lead post comprise a flat horizontally orientated plate positioned transversely across the lead post, the opposite edges of said plate being upturned to define roller mounting flanges, each pair of rollers including a transverse mounting axle, said flanges being defined with a series of transverse axle receiving holes therethrough for the mounting of said pairs of rollers.

7. The construction of claim 6 wherein said lead post is of a hollow upwardly opening rectangular configuration, said plate including a centrally located depending mounting unit closely received Within the upper end of said lead post, and means for fixing said mounting unit within said lead post.

8. The construction of claim 7 wherein each of said sections comprises a series of vertically extending rigid panels interconnected by full height flexible hinge means,

said panels being of a substantially constant width along substantially the full length of each section, said lead post being rigidly afiixed to a relatively narrower panel orientated transversely of the length of said sections, said relatively narrower panel in turn being hingedly engaged with each of said sections by means of a pair of rearwardly directed connecting panels engaged between the opposed edges of the transverse panel and the adjacent edges of the two section panels, said connecting panels also being of a width substantially narrower than the width of the section panels.

9. The construction of claim 3 wherein each pair of rollers is mounted for limited wobble movement relative to the rigid means connecting the roller units to the lead post whereby straight tracking orientation of the rollers within the tracks is retained notwithstanding the introduction of an off-center force on the lead post.

10. The construction of claim 1 wherein the rigid means connecting the roller units to the lead post comprise a flat horizontally orientated plate positioned transversely across the lead post, the opposite edges of said plate being upturned to define roller mounting flanges, each roller unit comprising a plurality of pairs of rollers, each pair of rollers including a transverse mounting axle, said flanges being defined with a series of transverse axle receiving holes therethrough for the mounting of said pairs of rollers.

11. The construction of claim 10 wherein said lead post is of a hollow upwardly opening rectangular configuration, said plate including a centrally located depending mounting unit closely received within the upper end of said lead post, and means for fixing said mounting unit within said lead post.

12. The construction of claim 10 wherein each of said sections comprises a series of vertically extending rigid panels interconnected by full height flexible hinge means, said panels being of a substantially constant width along substantially the full length of each section, said lead post being rigidly aflixed to a relatively narrower panel orientated transversely of the length of said sections, said relatively narrower panel in turn being hingedly engaged with each of said sections by means of a pair of rearwardly directed connecting panels engaged between the opposed edges of the transverse panel and the adjacent edges of the two section panels, said connecting panels also being of a width substantially narrower than the width of the section panels.

13. A support and guide assembly for the lead post of a two section hollow core folding door, said assembly comprising a flat transversely elongated plate, upturned flanges provided on and along the opposed side edges of said plate, each of said flanges having a plurality of transverse openings defined therethrough, a roller axle extending through each opening, and a pair of rollers mounted on each axle, one to each side of the corresponding flange, said pairs of rollers being positioned at spaced points longitudinally along each flange, and mounting means rigid with said plate for locked engagement with a lead post.

14. The construction of claim 13 wherein selected pairs of rollers mounted on each flange are oflset downwardly relative to the remaining pairs of rollers, said rollers all being of substantially equal diameters, said downwardly ofl'set pairs of rollers being particularly adapted for tracking on a lower tracking surface while the remaining pairs of rollers track on an upper tracking surface in opposed relation to the lower tracking surface.

15. Folding door construction comprising a pair of laterally spaced door sections, each section being defined by a series of vertically orientated hingedly interconnected panels, a lead post assembly interconnecting said sections at one end thereof, said lead post assembly comprising a vertically elongated lead post, a transverse panel of a width less than that of the section panels being rigidly connected to said lead post, and a pair of connecting panels, also of a width substantially less than the Width of the section panels, hingedly interconnecting the opposed edges of the lead post connected panel and the adjoining edges of the section panels, a roller assembly engaged with the upper end of said lead post, said roller assembly comprising a pair of laterally spaced upwardly directed roller units, each roller unit comprising a series of pairs of. rollers, a pair of elongated tracks orientated over the pair of roller units and rollingly receiving the pairs of rollers associated therewith, each of said tracks including means cooperating with the rollers for guiding the rollers for longitudinal movement therealong.

References Cited UNITED STATES PATENTS 3,126,943 3/ 1964 Giordani. 3,155,051 11/1964 Sherburne 16--87.2 X 3,312,273 4/1967 Adam et a1. 160345 3,447,584 6/1969 Smart 16084 FOREIGN PATENTS 560,591 6/ 1923 France. 10 700,271 11/1925 Great Britain.

- PETER M. CAUN, Primary Examiner US. Cl. X.R. 

